These are phrases of the form "__ as a __".
The completed phrases are in alphabetical order.

Answers

Spoiler:

Blind as a bat
Busy as a bee
Clean as a whistle
Clear as a bell
Cool as a cucumber
Cute as a button
Deaf as a post
Dry as a boneFit as a fiddle
Flat as a pancake
Fresh as a daisy
Hard as a rock
High as a kite
Light as a feather
Neat as a pin
Pale as a ghost
Pretty as a picture
Red as a beet
Sick as a dog
Skinny as a rail
Smart as a whip
Stiff as a board
Stubborn as a mule
Tight as a drum
Wise as an owl